I see a point in what fire007 says. Correct me if I am wrong, but the APROO Diver will be the first massive case in ceramic material. All other ceramic watches I can think of were thin-walled. Top Gun, some PAMs, the Hublots, what else am I forgetting?
As counter-intuitive as it may seem, the thicker and bulkier the ceramic body, the higher the chance of it breaking if not properly produced. That's because one increases the number of tiny defects which act as stress raisers inside the mass of ceramic material. Remember, ceramic is very hard, but with hardness comes brittleness. (There is no use in comparing the ceramic cases with the sapphire of our crystals. Even though the latter is also a ceramic, thus hard and brittle, the production of sapphire is strictly controlled, something we don't know yet about the AP ceramic case.)
